Foxes in Class I are friendly toward experimenters, wagging their tails and whining. In the sixth generation bred for tameness we had to add an even higher-scoring category. Members of Class IE, the "domesticated elite," are eager to establish human contact, whimpering to attract attention and sniffing and licking experimenters like dogs. They start displaying this kind of behavior before they are one month old.
It took them a long time to get them to mostly reproduce with those traits (the modern ones only reach 80%), but the traits appeared in 6 generations.
Although I do feel a bit moralistic about dog breeds that have been selected for specific physical appearance characteristics without much apparent attention given to the animals health. Pugs are a good (bad) example, the RSPCA takes a pretty dim view.
Papillons have only minor health concerns although patellar luxation, seizures, and dental problems can be issues. Additionally they can be at risk for PRA, intervertebral disk disease, and allergies. 
It amazes me a bit that "dogs" are all the one species, Canis familiaris (which translates from Latin to 'family dog', cute). I wonder what we could do with humans if we selectively bread them for hundreds of generations.
So the 2,000 that they have today doesn't say much about how many foxes they were breeding in the earlier generations (but over 50 generations the numbers culled probably do get into the thousands).
Edit. In most of Australia it is illegal to keep a pet fox, but in NSW you can if they are desexed and not released back into the wild . I still doubt AQIS will let me bring one in.
When they're old enough he releases them back into the wild.
The cats' expressions are priceless. :)